We have created a new type of search engine that searches on the full source code of webpages, not just the on-page text. It's called NerdyData (nerdydata.com) and we're launching today!
We even offer a search interface specifically for SEO's and marketers that allow you to search within specific HTML tags like meta descriptions and meta keywords.
About us: We're two 23 year olds who recently graduated from Stony Brook University in New York, and we are ridiculously passionate about making search better for our fellow nerds out there.
If you'd like to know more, you can email me at firstname.lastname@example.org
Thank you so much for you time!